(12) Weight: Approx. 650 grams (including the battery)
V. Technical characteristics and operating description of the insulation
tester
Accuracy:±% reading ± number, one-year warranty
Environment to guarantee the accuracy: 23
°
C±5
°
C, less than 75%RH
Rated measurement voltage, valid measurement range, and precision
Rated voltage Measurement range
Accuracy
250V 0.25M-400M
Ω
500V 0.5M
Ω
-4G
Ω
1000V 1.5M-40G
2500V 5M-40G
Ω
0.2M-200M
Ω
:±3%rdg±5,
200M-4G
Ω
:±5%rdg±5,
4G-40G
Ω
:±10%rdg±5
2
Display range
Rated voltage Display range (auto range )
Resolution
250V 4M/40M/400M
Ω
1k/10K/100K
Ω
500V 4M/40M/400M/4G
Ω
1k/10K/100K
/1M
Ω
1000V 40M/400M/4G/40G
10k/100K/1M
/10M
Ω
2500V 40M/400M/4G/40G
Ω
10k/100K/1M
/10M
Ω
Characteristics of the measurement terminal
Rated
voltage
Allowed range
of open circuit
voltage
The measurement resistance value that
can maintain lower limit of the rated
voltage
short circuit
current
250V 250K
Ω
(ERR is displayed when it is
less than 200K
Ω
)
500V 500K
Ω
(ERR is displayed when it is
less than 400K
Ω
)
1000V 1.5M
Ω
(ERR is displayed when it is
less than 1M
Ω
)
2500V
90%-110% of the
rated voltage
5M
Ω
(ERR is displayed when it is less
than 2M
Ω
)
Not less than
1.5mA
Usage for insulating resistance measurement
Danger
: If there is any measurement error, it may cause personal injury
and meter failure. Operate it only after read the operating instructions carefully
and thoroughly. Our company will take no responsibility for the accident not
caused due to any reason of our company.
Operating description
1. Safety information
1) Watch out for high-voltage electric shock. When completing the
insulating resistance test, remove the test cable only after making sure high
voltage across the tested object is less than 50V.
2) During measurement, do not touch the object under test and watch out for
high-voltage electric shock.
3) When test the insulating resistance, the object should not be electrified.
Make sure the to-be-tested object is securely earthed. Before test, it is necessary
to short-circuit and discharge two test terminals of the to-be-tested object.
4) When test the insulating resistance, make sure no external voltage is
applied to the test circuit.
5) Before starting test, make sure position of the range switch knob is correct
and the test cable is securely connected.
6) After press the high voltage key, high voltage from 250V to 2500V will
be output between L terminal and E terminal (depending on different models
and positions). Here, be sure not to touch the meter and exposed part of the
object under test. Otherwise, danger of electric shock would occur.
2
．
Insulating resistance test
1) Connection of the test terminals
Insert one end of the test pen with a high voltage test bar into L terminal
socket of the meter. Insert one end of the test cable with a test clamp into E
terminal socket of the meter. Insert one end of the test cable with a black test
pen (the pen with a clamp) G terminal socket of the meter. Make a good
connection respectively.
2) Test connecting cable
Connecting cable of E terminal socket of the meter is earthing cable
；
Connecting cable of L terminal socket of the meter (with a high voltage test bar)
is circuit cable
；
Connecting cable of G terminal socket of the meter (the pen with a clamp) is
shielding cable and connected to surface of the to-be-tested object to prevent
surface leakage and affect impedance test.
3) Rated voltage selection
Select a rated voltage you need in the insulating resistance test. Turn the range
switch knob to a corresponding voltage position, and press “SELECT” to
make selection among 1min/2min/10min according to test time requirement
4) Connect pen of the test bar to another terminal of the to-be-tested object.
Press high voltage switch (TEST/STOP). Here, the red indicator light turns
on, indicating high voltage output for test is connected. Actual high voltage
value can be displayed in the meter.
After the test is started, numerical value is displayed in the meter. The
displayed value is the insulating resistance value of the object under test. For
convenience of use, when the set test time comes, the meter cuts high voltage
off automatically, and locks and saves the measured result. When the
measured result is less than the set minimum resistance value under the
measurement voltage, “ERR” is displayed in the meter. If there is a need to
remeasure, press any key to release the lock status and start the measurement
over again.
Attention: do not short-circuit the two test pens with high voltage output or take
measurement of insulating resistance after high voltage is output. The
improper operation is very easy to generate spark, cause fire disaster, and
damage the meter.
Special attention in operation:
Before test, make sure the to-be-tested circuit is not electrified. Do not take
measurement of any electrified equipment or electrified circuit. During test,
dangerous voltage output exists in the meter. Be sure to operate it carefully.
Ensure the to-be-tested object is securely clamped and keep your hands away
from the test clamp before press TEST key to output high voltage.
Attention in operation:
When use 500V measurement voltage to measure resistance less than 2M
Ω
,
1000V to measure resistance less than 5M
Ω
, and 2500V to measure resistance
less than 10M
Ω
, measurement time must not exceed 10 seconds.
5) Power off
After the test is completed, release lock status of the meter and observe
voltage display value of the insulating resistance tester. When it is less than 50V,
turn the range switch knob to OFF position, and then remove the test cable. The
test is over.
Attention: the meter can not be turned off automatically when it is used as
an insulating resistance tester. Please turn the range switch knob to OFF
position after the test is over.
Notices in use of the insulating resistance tester
1. Brief introduction
The insulating resistance tester can be used to verify completeness of motor,
transformer, switching equipment, and coil and cable of electric equipment. For
example, when electric cable or switching equipment (low capacitance
equipment) is tested, time-related capacitive leakage current is not noticeable
and would quickly drop to zero. Within a short time (one minute or less), it will
reach a stable conductive leakage current quantity of, providing a good
condition for spot-check of reading/short-time impedance test.
In the other hand, time-related current will last for several hours when the
equipment under test is long cable, large-sized motor or generator (high
capacitance equipment). The current would cause ceaseless change of the
reading of the insulating resistance tester. It is impossible to obtain an accurate
reading. If trend analysis among readings can be made, for example, step
voltage or medium absorption test, the situation can be overcome. The analysis
doesn’t rely on a single reading, but on a large quantity of related readings. As
time-related current drops quickly when low capacitance equipment is tested,
results from multiply tests are the same. Therefore, use of the multiply test
method will waste time.
2, Test in assembly
The most important reason of the insulation test is to ensure the public and
individual safety. Through high voltage DC test among live wire, earthing and
earthing wire, you can eliminate short circuit or earthing phenomenon that is
dangerous to the human life. Usually, the test is performed after preliminary
equipment installation is completed. Performing the test can find connection
error and defective equipment, guarantee high quality installation, and prevent
fire disaster or explosion.
3. Test in maintenance
Another important reason of the insulation test is to protect and lengthen
service life of electric system and motor. Electric system is affected by such
factors as dust, grease, temperature, stress, and vibration for a long time. These
conditions may cause insulating deterioration, loss in production, and even fire
disaster. Regular maintenance and test can provide very valuable information
of system wear and tear status and help forecast system failure possibility.
Solving problems in time can guarantee that a system operates without any
fault and effectively lengthen service life of various equipments.
To obtain meaningful insulating resistance result, an electrician should check
the to-be-tested system carefully before take measurement. When the following
conditions are satisfied, the best results will be obtained:
1) Shut down the system or equipment and disconnect it from other circuits,
electric switches, capacitors, electric brushes, lightning rods, and circuit
breakers. Ensure the test is not affected by leakage current that flows through
switches and over-current protection components.
2) The temperature should be higher than dew point of the environmental air. If
the condition is not satisfied, a layer of water smoke will be formed in the
insulating surface. In some cases, it would be absorbed by insulating material.
3) In surface of the conductor there should be no carbon and other impurity that
are easy to form a conductor.
4) The applied voltage should not be too high. When low voltage system is
tested, too high voltage would cause overload or damage a insulator.
5) The to-be-tested system should be fully discharged to the earth. The earthing
discharge time should be approx. fivefold of the charge time.
6) Temperature influence is worth attention. As insulating resistance is in
inverse ratio with insulating material temperature (the higher the temperature is,
the lower the impedance is). The recorded impedance reading would be changed
by insulating material temperature. It is suggested to perform measurement in a
standard temperature of 20
℃
(68
o
F). Compare a reading with a result at a
temperature of 20
℃
according to conventional practice. with a temperature over
20
℃
, the impedance value at 20
℃
will be twofold of its reading every time the
temperature goes up for 10
℃
(18
o
F); with a temperature under 20
℃
, the
impedance value at 20
℃
will be one half of its reading every time the
